The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventor, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A network device is a device that processes data in a network. For example, common network devices include gateways, routers, bridges, switches, hubs, repeaters, and the like. In some applications, a communication cable may be coupled to a network device to permit the network device to communicate, via the communication cable, over the network. An interface between a communication cable and a network device is typically needed to couple the network device to the cable. However, the interface may be a source of an impedance mismatch between the network device and the combined impedance of the interface and communication cable. Impedance mismatches may lead to return loss, which corresponds to an unwanted loss of signal power at transitions between the network device, the interface, and the communication cable.
FIG. 1 shows a graph 10 showing an impedance of a network device in relation to frequency. The frequency shown in graph 10 corresponds to a frequency of operation of the network device. The impedance is shown on the y axis and the frequency is shown on the x axis of graph 10. As shown, the impedance varies with respect to frequency. At higher frequencies, the impedance variation increases. The impedance of the network device may be acceptable between 1 MHz and 125 MHz because the return loss due to impedance mismatch is acceptable. However, in a network device that communicates at 10 gigabits, the bandwidth may extend to 500 MHz. In this case, the impedance variance causes an impedance mismatch that leads to a large return loss across the wide frequency band.